Pain tolerance and threshold in suicide attempters: A systematic review and meta-analysis.

It has been hypothesized that individuals less sensitive to pain could be at higher risk of suicide. However, data on pain sensitivity in suicide attempters (SA) obtained using experimental procedures are heterogeneous. The aim of this systematic review and meta-analysis was to investigate and compare pain tolerance and threshold in SA (patients with lifetime history of suicide attempt), non-attempters (psychiatric controls, PC), and healthy controls (HC). A random effects meta-analysis was used to estimate the standardized mean differences using data from 16 studies that compared physical pain tolerance and threshold in SA and PC or HC. Pain tolerance and threshold were not significantly different in SA and PC. However, pain tolerance, but not threshold, was higher in SA than HC. Our findings do not support the hypothesis of an altered pain perception related as a trait for suicidal vulnerability, but rather suggest altered pain perception related to psychiatric vulnerability.

Subjects suffering from bipolar disorder taking lithium are less likely to report physical pain: a FACE-BD study.

BACKGROUND: Physical pain is a common issue in people with bipolar disorder (BD). It worsens mental health and quality of life, negatively impacts treatment response, and increases the risk of suicide. Lithium, which is prescribed in BD as a mood stabilizer, has shown promising effects on pain. METHODS: This naturalistic study included 760 subjects with BD ( FACE-BD cohort) divided in two groups: with and without self-reported pain (evaluated with the EQ-5D-5L questionnaire). In this sample, 176 subjects were treated with lithium salts. The objectives of the study were to determine whether patients receiving lithium reported less pain, and whether this effect was associated with the recommended mood-stabilizing blood concentration of lithium. RESULTS: Subjects with lithium intake were less likely to report pain (odds ratio [OR] = 0.59, 95% confidence interval [CI], 0.35-0.95; p = 0.036) after controlling for sociodemographic variables, BD type, lifetime history of psychiatric disorders, suicide attempt, personality traits, current depression and anxiety levels, sleep quality, and psychomotor activity. Subjects taking lithium were even less likely to report pain when lithium concentration in blood was ≥0.5 mmol/l (OR = 0.45, 95% CI, 0.24-0.79; p = 0.008). CONCLUSIONS: This is the first naturalistic study to show lithium's promising effect on pain in subjects suffering from BD after controlling for many confounding variables. This analgesic effect seems independent of BD severity and comorbid conditions. Randomized controlled trials are needed to confirm the analgesic effect of lithium salts and to determine whether lithium decreases pain in other vulnerable populations.

Mediation effect of anxious attachment on relationship between childhood trauma and suicidal ideation sensitive to psychological pain levels.

BACKGROUND: Childhood trauma (CT), depression, and psychological pain are known predictors of suicidal ideation. Recent literature additionally highlights the importance of the attachment system. METHODS: We aimed to predict suicidal ideation through CT, attachment, and psychological and social pain by using mediation models aiming to predict suicidal ideation through CT (predictor) and attachment (mediator). In the same models, we introduced psychological or social pain as a moderator of the relationship between attachment, CT, and suicidal ideation. We included 161 depressed patients and assessed depression, attachment, CT, suicidal ideation, psychological pain, and social pain. RESULTS: We found (1) a complete mediating effect of anxious attachment (a2b2 = 0.0035, CI95% = [0.0010; 0.0069]) on the relationship between CT on suicidal ideation, and (2) a significant complete conditional mediating effect of anxious attachment and psychological pain (index of moderated mediation VAS: 0.0014; CI95% = [0.0002; 0.0032]) but not social pain on the relationship between CT and suicidal ideation. Both models were controlled for history of suicidal attempt, depression severity, and sex. CONCLUSIONS: Our results suggest a developmental profile of suicidal ideation in mood disorder that is characterized by the presence of CT and insecure attachment, especially anxious attachment, that is sensitive to experiences of psychological pain. Nevertheless, we cannot conclude that avoidantly attached individuals do not present the same mechanism, as they may not disclose those ideas.

Sensitivity to ostracism is blunted in suicide attempters only when they report suicidal ideation.

BACKGROUND: Modified pain perception is at the core of many theories on suicide; however, studies on the relationship between pain perception and suicidal behavior (attempt) have produced contradictory results. In this experimental study, we investigated whether physical pain and social pain are concomitantly influenced by suicidal ideation (SI) and past suicidal behavior. METHODS: 155 inpatients with depression (90 with and 65 without past history of suicide attempt) were included. They underwent thermal stimulation of the skin to assess physical pain tolerance and played the Cyberball game to assess their sensitivity to ostracism (social pain). Participants self-assessed current SI through the specific item in the Beck Depression Inventory. RESULTS: Pain tolerance was not associated with history of suicide attempt, current SI, and their interaction. Social pain was associated with the interaction between history of suicide attempt and current SI. Social pain was decreased in suicide attempters, compared with non-attempters, only when they reported current SI. LIMITATIONS: Cyberball game may not be representative of everyday stress and ecological social context. CONCLUSIONS: Unlike what suggested by many theories, pain tolerance does not seem to be necessary to attempt suicide. Suicide attempters with current SI displayed blunted sensitivity to ostracism and could be less willing to restore social affiliation compared with non-attempters.

Depression and approach-avoidance decisions to emotional displays: The role of anhedonia.

Depression is linked to dysfunctional appetitive and aversive motivational systems and effort-based decision-making, yet whether such deficits extend to social decisions remains unclear. Participants (23 non-depressed, 48 depressed - 24 with a past history of suicide attempt) completed a social decision-making task consisting in freely choosing whether to approach or avoid individuals displaying happy or angry expressions. Occasionally, participants had to make a further effort (change button press) to obtain the desired outcome. All participants preferentially avoided anger on their first choice. Yet, depressed patients less often chose to approach happy individuals, as a function of anhedonia severity. Depressed patients were also less inclined than controls to change their response when the anticipated outcome of their first choice was undesirable (approach angry and avoid happy). Again, such effect correlated with anhedonia severity. Our results support that both altered valuation and willingness to exert effort impact approach-avoidance decisions in social contexts in depression. On this basis, we propose a new integrating framework for reconciling different hypotheses on the effect of depression and anhedonia on motivational responses to emotional stimuli.

Effect of mirror therapy in the treatment of phantom limb pain in amputees: A systematic review of randomized placebo-controlled trials does not find any evidence of efficacy.

BACKGROUND AND OBJECTIVE: Phantom limb pain (PLP) concerns >50% of amputees and has a negative impact on their rehabilitation, mental health and quality of life. Mirror therapy (MT) is a promising strategy, but its effectiveness remains controversial. We performed a systematic review to: (i) evaluate the effectiveness of MT versus placebo in reducing PLP, and (ii) determine MT effect on disability and quality of life. DATABASES AND DATA TREATMENT: We selected randomized-controlled trials in five databases (Medline, Cochrane Library, CINAHL, PEDro and Embase) that included patients with unilateral lower or upper limb amputation and PLP and that compared the effects on PLP of MT versus a placebo technique. The primary outcome was PLP intensity changes and the secondary outcomes were PLP duration, frequency, patients' disability and quality of life. RESULTS: Among the five studies included, only one reported a significant difference between the MT group and control group, with a positive MT effect at week 4. Only one study assessed MT effect on disability and found a significant improvement in the MT group at week 10 and month 6. CONCLUSIONS: Our systematic review did not allow concluding that MT reduces PLP and disability in amputees. This lack of strong evidence is probably due to (i) the low methodological quality of the included studies, and (ii) the lack of statistical power. Future trials should include a higher number of patients, increase the number and frequency of MT sessions, have a long-term follow-up and improve the methodological quality. SIGNIFICANCE: Recent meta-analyses concluded that MT is effective for reducing phantom limb pain. Conversely, the present systematic review that included only studies with the best level of evidence did not find any evidence about its effectiveness for this condition. We identified many ways to improve future randomized-controlled trials on this topic: increasing the number of participants, reducing the intra-group heterogeneity, using a suitable placebo and intensifying the MT sessions and frequency.

Self-Reported Pain and Emotional Reactivity in Bipolar Disorder: A Prospective FACE-BD Study.

In patients with bipolar disorder (BD), pain prevalence is close to 30%. It is important to determine whether pain influences BD course and to identify factors associated with pain in BD in order to guide BD management. This naturalistic, prospective study used data on 880 patients with BD from the French FACE-BD cohort who were divided into two groups according to the presence or absence of pain. Multivariate models were used to test whether pain was associated with affective states and personality traits while controlling for confounders. Then, multivariate models were used to test whether pain at baseline predicted global life functioning and depressive symptomatology at one year. At baseline, 22% of patients self-reported pain. The pain was associated with depressive symptomatology, levels of emotional reactivity in a quadratic relationship, and a composite variable of personality traits (affective lability, affective intensity, hostility/anger, and impulsivity). At one year, the pain was predictive of depression and lower global life functioning. Pain worsens mental health and well-being in patients with BD. The role of emotions, depression, and personality traits in pain has to be elucidated to better understand the high prevalence of pain in BD and to promote specific therapeutic strategies for patients experiencing pain.